Dipyridylium quaternary dihalide halogen complexes

ABSTRACT

Halogen complexes of dipyridylium quaternary dihalides which are bacteriocidal and herbicidal agents and useful as defoliants and desiccants, particularly as cotton defoliant-desiccants. This invention relates to novel quaternary dihalide halogen complexes, more particularly to halogen complexes of N,N&#39;&#39;ethylene-2,2&#39;&#39;-dipyridylium dihalides and to their use as herbicides, especially for growing vegetation, which is substantially severely damaged or completely destroyed by herbicidal treatment therewith, and as defoliants and desiccants, particularly as superior harvest aid chemicals having special application in the preparation of cotton for harvest by defoliation and desiccation without concurrent suppression of the opening of mature bolls of cotton plants treated therewith.

United States Patent Thomas et al.

[54] DIPYRIDYLIUM QUATE RNARY DIHALIDE HALOGEN COMPLEXES [72] Inventors:Robert M. Thomas; Fred R. Gerns; John L. Sands, all of West Lafayette,Ind.

[73] Assignee: Great Lakes Chemical Corporation, West Lafayette, Ind.

[22] Filed: Jan. 15, 1971 [21] Appl.No.: 106,934

Related U.S. Application Data [63] Continuation-impart of Ser. No.770,082, Oct. 23,

1968, Pat. No. 3,641,041.

[52] U.S. Cl. ..260/2S0 R, 260/296 D, 260/296 H,

71/92 [51] Int. Cl. ..C07d 51/02 [58] Field of Search ..260/296 H, 296D, 250 R [56] References Cited UNITED STATES PATENTS 3,202,500 8/1965Homer ..7l/92 1 July 4, 1972 3,308,124 3/1967 Braunholtz et al ..260l2503,311,535 3/1967 Whipp ..424/250 3,332,959 7/1967 Braunholtz..........260/296 Primary Examiner-Alan L. Rotman Attorney-Gordon W. l-lueschenand Talivaldis Cepuritis [57] ABSTRACT Halogen complexes of dipyridyliumquaternary dihalides which are bacteriocidal and herbicidal agents anduseful as defoliants and desiccants, particularly as cottondefoliantdesiccants.

5 Claims, No Drawings DIPYRIDYLIUM QUATERNARY DIHALIDE HALOGEN COMPLEXESRELATED APPLICATION This application is a continuation-in-part of ourprior-filed co pending application, Ser. No. 770,082, filed Oct. 23,1968, in which restriction was required, now U.S. Pat. No. 3,641,041,issued Feb. 8, 1972.

OBJECTS OF THE INVENTION It is an object of the invention to providenovel dipyridylium quaternary dihalide halogen complexes. Another objectis the provision of methods and compositions for their use as herbicidesand defoliant-desiccants. Other objects will be apparent to thoseskilled in the art to which this invention pertains.

BACKGROUND OF INVENTION Certain halogen addition products of quaternaryhalides are known in the art. They have been used to sterilize water(u.S. Pat. No. 3,152,073), as germicidal detergents (U.S. Pat. No.2,746,928) as antibacterial and anti-fungal agents (U.S. Pat. No.2,868,686) and as gerrnicides (U.S. Pat. No. 3,028,301, U.S. Pat. No.2,679,533). Two of the dipyridylium dihalides used as starting materialsto produce the novel halogen complexes of this invention, viz.,N,N'-ethylene-2,2'-dipyridylium dibromide andN,N'-dimethyl-4,4'-dipyridylium dichloride, are used commercially asherbicides. (See U.S. Pat. No. 2,823,987 and U.S. Pat. No. 2,972,528.See also U.S. Pat. No. 3,202,500 and U.S. Pat. No. 3,332,959.)

As stated, certain halogenated quaternary ammonium complexes are knownin the art. The tetrabutyl ammonium tribromide type complex is disclosedand studied in Journal American Chemical Society, Volume 73, page 425(1951). It was there recognized that polyhalide complexes ofmonoquatemary ammonium halides have long been known. In many cases suchcompounds have been prepared as solid derivatives of the parentcompound.

DESCRIPTION OF THE INVENTION The following is a description of themanner of making and using and the best mode contemplated of carryingout the invention.

The quaternary dihalide halogen complexes of this invention are powerfulherbicides. In contrast to their parent starting quaternary dihalides,they are superior defoliating-desiceating agents which are especiallyuseful as cotton defoliantdessicants and which exhibit no suppression ofthe opening of mature bolls of cotton plants treated therewith. Thosewhich are bromine complexes are particularly useful for this purpose.The discovery that the activity of the starting quaternary dihalides isimproved and altered in this manner by conversion to the halogencomplexes of this invention is of substantial importance in the cottonindustry because harvest aid defoliation and desiccation procedurebetter prepares the mature cotton plants for mechanical harvest byreducing the trash collected along with the cotton bolls and eliminatinggreen leaves which would result in staining of the cotton linters duringharvest. Whether desiccation or defoliation is preferred in a particularcase depends upon many conditions and factors, including the type ofharvesting equipment to be employed, but in any event such trash andgreen leaf reduction obviously up-grades the quality of the harvestedcotton, and any improved harvest aid in this area would consequently beof considerable importance. One especially critical factor in the use ofsuch a desiccant or defoliant as a harvest aid is its effect on theopening of the mature cotton bolls, which should not be impeded by theharvest aid agent of procedure employed. The halogen complexes of thisinvention are clearly superior to the parent starting quaternarydihalides, inter alia, in this respect. Their high degree ofdesiccant-defoliant effectiveness, especially coupled with theirnon-interference with mature boll opening, certainly could not have beenpredicted on a basis of chemical structure. Their eflicient defoliatingand desiccating activity also renders them useful to rapidly clearjungle areas and railroad and utility rights-of-way.

In addition, the halogen complexes of this invention have anti-microbialactivity and can be used as anti-bacterial agents. They are activeagainst gram positive and gram negative bacteria.

The compounds of this invention can be used as defoliantdesiccants byapplying them to the area to be defoliated in an amount effective to atleast substantially defoliate and/or desiccate the flora of the treatedarea. Generally, up to 4 pounds per acre is employed. Higher amounts arealso effective but are wasteful and unnecessarily expensive andordinarily do not result in increased defoliation. Generally, an amountof the selected compound between about 0.1 and 2.0 pounds per acre,preferably between 0.2 and 1.0 lb/acre, is employed, the exact amountdepending on the type of plants to be defoliated, their density and thepercentage lost by drift during application. For example, mature cottonplants planted at normal densities can be sufiiciently defoliatedpercent) to permit mechanical picking with almost no pin trash byapplying N,N-ethylene, 2,2'-dipyridylium bistribrolnide (GLC 506)uniformly thereto at a rate of 0.125 to 0.2 lb/acre. At higher treatmentlevels (0.25 to 3 lbs/acre), -98 percent defoliation can be achieved.Lower treatment levels appear to favor desiccation, whereas highertreaunent levels appear to favor defoliation.

The compounds of this invention can also be used as herbicides byapplying them to the area to be devegetated. Usually they are appliedfor this purpose in an amount effective to at least substantiallyseverely damage and preferably kill the flora of the treated area.Generally, an amount less than 25 pounds per acre is employed. Higheramounts are also effective but ordinarily do not result in increaseddefoliation. Usually, the selected compound is employed in an amountbetween about 0.2 and 10 pounds per acre, preferably between about 0.5and 5 pounds per acre, the exact amount depending on the exact resultdesired, the type of plants to be killed, their density, age and extentof growth, and the percentage of herbicide lost by drift duringapplication. For example, growing pigweed, tomato, radish, cucumber, redkidney bean plants, wheat, Johnson grass, oats, cotton, etc., are allkilled or severely damaged by applying a complex of the invention, e.g.,l,l'-ethylene-2,2'-dipyridylium bistn'bromide (GLC 506), uniformlythereto at an early post-emergence stage at a rate of 0.5 to 2 poundsper acre. At higher treatment levels (2.5 to 10 pounds per acre),percent kill of virtually all types of plants can be achieved. Exceptfor their water and most organic solvent insolubility and their abilityto halogenate compounds mixed therewith which are readily halogenatablewith elemental halogen, the compounds of this invention can be used asherbicides in the same manner as known herbicides, e.g., thecorresponding starting dipyridylium quaternary dihalides. For adescription of such a manner of using, see U.S. Pat. Nos. 3,202,500 and3,332,995.

The exact results, whether herbicidal or cotton defoliantdesiccantresults, and the exact amount of active material of the inventionnecessary to accomplish the same, will as usual vary somewhat dependingupon climatic conditions such as temperature and humidity.

In order to apply the halogen complex uniformly, whether as adefoliant-desiccant or herbicide, it is usually applied in combinationwith an inert or synergizing carrier, which may be either solid orliquid but which is preferably solid and puI verulant, at least beforedilution and application. Because the complex can rapidly lose itselemental halogen in the presence of readily halogenated compounds, thecarrier (if susceptible to halogenation) is usually mixed with thehalogen complex just prior to its application to the flora to betreated, or the complex is applied dry mixed with a powder carrier whichwill adhere to the plants. After admixture with the selected carrier,the composition is applied in any conventional manner to the flora to betreated. It can be applied as a suspension in water or in a non-ioniccarrier, e.g., dimethylformamide, gasoline, kerosene, or light oil.

In any application of the compounds of the invention to flora, e.g., forhebicidal, defoliant, desiccation or wilt purposes, especially when inliquid suspension form, it is advantageous to employ a non-ionicsticker-spreader (adherent) of the du Pont WK (dodecyl ether ofpolyethylene glycol) type or the Colloidal Chemical Corp. Multifilm X-77(compounded product of alkyl aryl polyethoxyethanol and free fattyacids) type, and such material is most advantageously incorporated inliquid preparations just prior to use.

In addition to the foregoing, the compositions of the invention mayadvantageously contain inert sticker-Spreaders or adherents forincreasing adherence of the composition to the plant, inert fillers ordiluents such as silica, calcium silicate, magnesium silicate, clays,gypsum and the like, inert dispersants or wetting agents, and the like,as more fully illustrated hereinafter, as well as other non-reactiveingredients having an additive synergistic or independent herbicidaland/or desiccant-defoliant effect, e.g., Paraquat or Diquat, if desired.

The active compounds of this invention areN,N'-lower-alkylene-dipyridylium and N,N-diloweralkyl-dipyridyliumdihalide halogen complexes, i.e., hexahalides or bistrihalides, whichcan be represented by the following generic structural formula:

wherein R and R are lower-alkyl of one to eight carbon atoms andpreferably one to three atoms, inclusive, when the dipyridylium group is3,3'- or 4,4'-dipyridylium, and collectively alkylene of one to fourcarbon atoms and preferably two or three carbon atoms, inclusive, whenthe dipyridylium group is 2,2'-dipyridylium; Hal; is a trihalide ion inwhich the halogen has an atomic weight from 35 to 80, inclusive, e.g.,Br ClBrf, C1 81", preferably Br For example, the dipyridylium moiety canbe 2,2-, 3,3-, 4,4- or mixtures thereof. When the dipyridylium group is3,3- or 4,4'-, R and R each can be CH C l-l n-C H,, iC H,, t-butyl, oroctyl. When the dipyridylium group is 2,2'-, R and R collectively can bemethylene, ethylene trimethylene, propylene, etc. The halogen in Hal;can be chlorine, bromine or a combination of chlorine and bromine.

The following are representative compounds of this invention defined bythe above formula.

The presence of non-interfering functional groups on the alkyl groupsattached to the nitrogen atoms of the 3,3'- and 4,4'-di-pyridyliummolecules and/or an alkyl group on one or more of the dipyridylium ringcarbon atoms will not affect the usefulness of the dipyridylium dihalidehalogen complexes as halogenating and herbicidal agents. Suchsubstituted compounds are therefore equivalents of the correspondingunsubstituted compounds. For example, the 2,2-dipyridylium compounds canhave a lower-alkyl, preferably methyl, group at one or more ofthe 4, 5,6, 4', 5 and 6' positions and the 4,4- dipryidylium compounds at one ormore of the 2, 3, 5, 6, 2, 3, 5 and 6' positions, and one or both butpreferably only one of R and R is lower-alkyl in which the terminalcarbon atom is substituted, e.g., with halogen, carboxyl,carbolower-alkoxy, phenyl, substituted phenyl, e.g., halophenyl,bromophenyl, nitrophenyl, tolyl, xylyl, etc.

Such compounds are solids, usually crystalline and colored when they areformed from elemental halogen. They are substantially insoluble in waterand most organic solvents. The elemental halogen used to form thetrihalide anion is titratable and, when formed from two molarequivalents of halogen, the titer is usually -98 percent of theory.Because the halogen is titratable, they can be used as halogenatingagents.

Such compounds are prepared by mixing about two molar equivalents of theselected halogen or mixture of halogens, e.g., C1 Br ClBr, with theselected starting diquatemary dihalide. This can be conducted in thepresence of a solvent normally used for halogenation reactions, e.g.,glacial or aqueous acetic acid, chloroform, carbon tetrachloride, wateror aqueous NaBr or NaCl. The choice of solvent is determined by thesolubility of starting quaternary salt therein. For this reason, aqueoussystems are generally preferred.

The reaction is preferably conducted at between l0 and 25 C., the lowertemperature limit being determined by the solubility of the reactants inthe selected solvent system and the upper temperature limit beingdetermined by the rate of decomposition of the product and/or sidereactions which may develop at higher temperatures.

If a mixed elemental halogen complex is desired, the halogens can beadded concurrently or successively in amounts calculated to produce thedesired molar ratio, or halogen in the starting diquatemary dihalide canbe allowed to remain therein by use of less than two moles of alkalimetal halide, or use of a metal halide containing the same halogen as inthe starting dihalide, but different from the halogen of the elementalhalogen employed.

If the starting quaternary dihalide is dichloride, simultaneously withthe formation of the halogen, e.g., bromine, complex, it can be reactedwith two molar equivalents of alkali metal bromide, e.g., NaBr or KBr,to form the quaternary hexabromide. Reaction with one molar equivalentof the alkali metal salt produces a mixed quaternary dihalide complex.

The starting quaternary dihalides are prepared by reacting 2,2'-, 3,3'-or 4,4'-dipyridyl with an amount of the selected alkylating agentsufficient to quaternize both nitrogen atoms. Thus, at least two molarequivalents of the selected alkyl chloride or bromide and at least onemolar equivalent of the selected alkylene dichloride or dibromide isemployed. Ordinarily, a large excess of these amounts is employed.Conventional quatemizing conditions are used. See US. Pat. Nos.2,823,987, 3,202,500 and 3,332,959, Homer et al., J. Chem. Soc. (1960)2498.

The following illustrate the making and using of the compounds of thisinvention which is not limited thereto.

Preparation N,N-trimethylene-2,2'-dipyridylium dibromide A mixture of2,2'-dipyridyl (0.077 mole) and 1,3-propylene dibromide (0.39 mole) wasstirred under reflux for hours.

Acetone was added and the product which precipitated was 5 collected byfiltration, recrystallized and decolorized with Darco activated charcoalin boiling methanol. The product was isolated in 94 percent yield in twocrops melting at 322 and 317, respectively.

EXAMPLES l-3 dipyridylium dibromide to 249 g. of bromine in 1,500 ml. of

H 0 containing 200 g. NaBr. The complex which precipitated immediatelywas collected, washed with water and air dried, yielding 962 g. (92.5percent) of the dibromine complex. Halogen titration with KI-thiosulfatein the usual way showed 94.5 percent of theory of titratable halogen.

solution of g. (0.22 mole) of bromine and 22.5 g. (0.22 mole) of sodiumbromide in 60 ml. of water. The orangecolored bromine complexprecipitated immediately. It was collected by suction filtration andwashed with water.

Titration of bromine by the standard thiosulfate method showed an activebromine titer of 95 percent of theory.

EXAMPLE 6 l 0 N,N-Ethylene-2,2-dipyridylium bischlorodibromide Bromine,88 g. (0.55 mole), was introduced into a solution of 32.2 g. (0.55 mole)of sodium chloride in 250 ml. of water. A solution of 64.3 g. (0.25mole) of N,Nethylene 2,2- dipyridylium dichloride in 158 g. of water wasthen added with 15 stirring. The yellow product precipitated.

Upon washing with water and drying, the product titrated 85 percent oftheory halogen.

PHYSICAL COMPARISON OF COMPOUNDS OF THE INVENTION WITH PARENT 1,1-din1ethyl-4, 4-dipyridy1ium bistribromide (commonly,N,N'-di1nethyl-4,4-dipyridylinm bistribromide).

EXAMPLE 4 N,N-Dimethyl-4,4-dipyridylium Bischlorodibrornide A solutionof 64.3 g. (0.25 mole) N,N'-dimethyl-4,4'- dipyridylium dichloride in160 g. of water was added with stirring to a solution of 88 g. (0.55mole) of bromine and 32.2 g. (0.55 mole) of sodium chloride in 250 ml.of water.

The yellow-orange bromochloro complex precipitated from the solution.Upon washing with water and drying, the complex titrated 82% of theoryhalogen.

Preparation N,N'-Di-n-propyl-4,4-dipyridylium dibromideN,N-Dipropyl-4,4-dipyridylium dibromide was prepared by stirring amixture of 15.6 g. (0.1 mole) of 4,4'-dipyridyl and g. (0.407 mole) ofn-propyl bromide in 100 ml. of npropano] for 24 hours under reflux. Thereaction mixture was stripped to dryness under vacuum and the residueslurried with acetone. The product was filtered and washed with acetone.

EXAMPLE 5 N,N'-Di-n-propyl-4,4-dipyridylium bistribromide A solution of40.2 g. (0.1 mole) of N,N'-di-n-propyl-4,4'- dipyridylium dibromide in100 ml. of water was stirred into a 50 change in water solubilityindicates a change in the ionic nature of the quaternary when complexedwith bromine. Table II shows a comparison of physical properties of thecompound of Example I and its precursor.

TABLE I1 Physical Differences Between Bromine Complex GLC 506 and itsParent Quaternary Salt GLC-D a. Color GLC-S06-yellow GLC-D-greenishyellow b. Melting Points GLC506-l95 C. (95% titer,

as of theory) 6 5 GLC-D-320" C.

c. Solubility GLC-506 GLC-D DMSO sol. sol. benzene insol. insol. aceticacid insol. insol. methylcyclohexane insol. insol.

carbon tetrachloride insol. insol. tetrahydrofuran insol. insol. waterinsol. sol. dimethylformamide sol. insol.

d. Raman spectra, in solution and in the solid state, show the productGLC-506 to contain the tribrornide anion [Br-Br-Brl' The brominecomplexes of Examples 1 and 3 were field tested as cottondefoliant-desiccants under the code numbers 506 and 514, respectively.

Because of their insolubility in water and other common solvents, thetest compounds were made up into 50 percent wettable powder formulationsfor field test purposes. These are recommended for use upon dilutionwith water in amount up to about 50 gallons per acre, but preferably nomore than about 20-30 gallons per acre, with an application rate of025-4, preferably 0.5-3, pounds of wettable powder per acre. Thewettable powders contained 50 percent by weight of active ingredientplus 50 percent by weight of a premix preparation of the compositionHiSil (silica) 92 percent, Marasperse N (sodium lignosulfonate) 4percent, and Pluronic L61 (ethylene oxide condensate with hydrophobiccondensate of propylene oxide and propylene glycol (4 percent). Tenpercent emulsion concentrates in DMF (dimethylformamide) were alsoprepared using as emulsifier 10 percent of a 50:50 ratio of Span(sorbitan ester of higher fatty acid) and Tween 80 (polyoxyethylenesorbitan monooleate). Only 506 was in complete solution in thisemulsifiable concentrate. About 1 to 2 percent solids appeared toprecipitate in the case of the 10 percent emulsion concentrate of 514.Because the complex decomposes in this carrier, it was made up justprior to use.

The field application was made on October 18, near Greenville,Mississippi. The application was tractor applied by means of overheadnozzles (no drop nozzles) at a gallonage of 39 G.P.A., a pressure of 25p.s.i. to reduce drift in the wind since the wind at the time ofapplication was approximately 10 m.p.h. with gusts up to 15 m.p.h.

The cotton used in the test was Stoneville 213 planted on a 4 X 4 schemewith rows 60 feet in length. At the time of treatment, the cotton was 4or 5 feet in height with 60 to 70 percent open bolls. From the generalappearance of the field, an estimate of final yield would be on theorder of one and onehalf bales per acre. The test plots were randomizedconsisting of 60 foot rows with 3 replicates. The field and the finalresults were very uniform and consistent.

First records were made on October 24, with final defoliation dataobtained on November 4.

On October 24 data were recorded re P.R. phytotoxicity Rating) using ascale of 0 to in which 10 indicates all leaves were killed and 0indicates no effect. Percent defoliation (DEF) and percent desiccation(DES) was also determined. Final data on defoliation were recorded onNovember 4. Because of a severe frost which occurred the night before,it was not possible to obtain final data on percent desiccation. Someherbicides are so phytoxic they inhibit the natural opening of thebolls, which is a very serious detriment to their use as a harvest aidon cotton. Therefore, on November 10 a count was made on the number ofunopened bolls per plant. Data accumulated in the field are recorded inTable III.

TABLE III Defoliant Activity of 506 and 514 October 24 Nov. 10 Nov. avg.No. Rate, Percent 4 peroi unop- Chcmiciil lbs./ cent ened bollsformulation acre P R DEF DES DEF plant 514 DMF (10%E.C.) 2 i0 50 50 98+0 1 10 75 25 85 0 0+ 85 00 0 M 7 4 80 0 80 0 506 DMF (10%E.C.) 2 10 7598 0 1 10 60 40 98 0 A 9+ 80 20 95 0 A 7 4 85 0 85 0 514 50% \vettablc 210 80 20 98 0 powder. 1 10 00 4O 80 0 A 0+ 85 15 90 0 $4 7 90 0 so 0 50050% \Vcttnblc 2 10 10 90 98 0 powder. 1 10 10 00 85 0 .H- 85 15 90 0 l i7 100T 0 100T 0 l urnqlliti i ii\S./il1li.) J .2 HI 0 100 h(N.N-(linwi.l| vll 10 (l 100 50 o 4.-llipyri(l\'|ilnn 10 00 40 80 .3

TABLE III (0nlinucd l)eioliant Activity of 506 and 514 1 Leavespartially loose.

2 Apparently not enough chemical reached bottom leaves.

3 Some burn on green bolls.

4 lb. rate would have picked very well with this degree of defoliationwith almost no pin trash.

From the P. R. values there appeared to be no significant differencebetween any of the materials tested with respect to phytotoxicity to theleaves and the plants, except at the low treatment level of one-quarterlb/acre where 506 and 514 were measurably more phytotoxic than Diquat(N,N'- ethylene-2,2'-dipyridylium dibrornide) and Paraquat (N,N-dimethyl-4,4-dipyridlium dichloride). However, very significantdifierences in percent defoliation can be observed. in the case ofParaquat and Diquat, 6 days after application there was essentially nodefoliation at effective herbicidal dosage levels (Phytotoxicity Ratingof at least 7). Their action was essentially desiccation only. On thesame date, both 506 and 5 l 4 produced -90 percent defoliation so that avery marked and significant difference between the action of 506 and 514and the action of the commercial herbicides Diquat and Paraquat wasapparent.

On November 4, both 506 and 514 had produced 98 percent plus defoliationat the 2 pounds per acre level of application and to percent defoliationat one-half pound per acre. 514 as a wettable powder produced 90 percentdefoliation, even at the %-pound-per-acre-rate. On November 10, verysignificant date was obtained with respect to bolls opening. With 514and 506, complete opening of the bolls occurred at all dose levels. WithDiquat and Paraquat a high number of bolls remained unopened at theirmost effective phytotoxic levels.

The following data were obtained in an evaluation of harvest-aidchemicals tested at Stoneville, Miss.

1. Cultural:

Cotton variety: DPL-l6 Planting dates:

A. April 24 B. May 5 Soil type: Bosket fine sandy loam Fertilization:500 lbs/A, l0-20-10, at planting Plant population: 39,000/AcreIrrigations:

A. August 7 B. August 4 Plant condition: Drought stressed, 3-4 ft. tall,cut-out Flowering and fruiting: Normal Lint production: Approximately500 lbs/Acre 11. Application:

Rig: Hahn Hi-Boy Nozzles: 2 X 12 tips per row (1 over row, 1 overmiddle) Pressure: 90-100 psi Speed: 2- /mph Gallonage: 36 gals/Acre Plotsize:

A. Two 2-row plots, ft. long B. Two 4-row plots, 66 ft. long Date:

A. September 15 B. October 15 Treatment ratings (days after treatment):

Photographs taken (days aftertreatment) 90, good." In contrast, the bestavailable commercial A. O, 7, 14 defoliant, DEF (TM), at 2 pints peracre 3 days after applica- B. 0, 7 tion was rated only slight,. after 7days good," and after 10 III Results: y 0,g

TEST NO. 1 TABLE IV R t lorccnt defoliation and desiccation after an, Chemicul lbs./acrc 1 day 2 days 4 days 8 days 14 days 1% 0 50A 75A 90A 90A0 20K 20A 20X 40A 50A 25W 60X 40A 50X 75A 10X 80A 5X 1 saw 70X 50A sex7011 20X 75A X 2 sow 100x 40A 60X 60A 40X 70A 30X 0 5X A 40A 50A V 40w70X 40A 20X 60A 75A 1 60W 95X 50A 50X 80A 15X 85A 10X 2 100W 100x 20A80X 75X X 80A +,20X

1 Percent abscission (A).

2 Percent desiccation (X).

3 Percent wilted (W). *'IMcommercial deioliant.

TEST NO. 2 (B) TABLE v Percent defoliation and desiccation after- Rate,

Chemical lbs/acre 4 days 8 days 12 days 1% 70A 85A 95A 60A 5X 75A 5X 75A4- 5X 4 70A 10X 85A 15X 85A 15X 1 65A 35X 75A 25X 80A 20X 75A 15X 85A15X 85A 15X 1 70A 25X 75A 25X 80A 15X 1 Percent defoliation (A). 2Percent desiccation (X). *TMTQL BIIQKQPJ FML. H

IV. Discussion:

Each chemical was mixed with a 3 gallon volume of water just prior toapplication. No problems were encounted in mixing or applying any of thechemicals when the agitation system of the spray machine was used.Compounds 506 and 514 were provided in the form of a silica(l-liSil)-based 50% wettable powder. A non-ionic sticker-spreader (X-77)was incorporatcd in the liquid preparation just prior to use, at a rateof ca. one-half pint per 100 gallons.

Both 5 06 and 514 treatments at acre rates of one-half lb. or higherresulted in considerable wilting of leaves within the first 24 hours,and by the end of 48 hours theseleaves were'desiccated. Most of thesedesiccated leaves defoliated by the end of 14 days. The observed wiltanteffect is particularly interesting and desirable from the standpoint ofenabling quick harvesting, which is of great interest in certain areas,such as Northern and Western Texas, where entire crops are lost orsubstantially lost each year because of storms which occur after thebolls are sufiiciently developed for harvesting, but before the leavescan be dropped or desiccated by previously available agents andprocedure.

The amount of defoliation indicated occurred by the fourth day afterapplication, and the leaf drop increased gradually for the next 10 daysto a high of 75-80 percent in some plots. in most cases, the 20-25percent undefoliated leaves were desiccated and stuck" to the plant.

Undesirable regrowth on the 506- and 514-treated plants was no differentfrom those treated with a phosphate type defoliant. The terminal buds onplants treated with the higher rates (one-half lb. or higher) of 506 and514 appeared to have been killed. I

There was no apparent lint stain in any of the treated plots.

in a similar series of tests conducted in substantially the same mannerat Shafter, California, using mature SJl-Acala cotton, in which thedegree of desiccation (leaf) and degree of desiccation (boll) wasrecorded, compound 514 at 1.0 lb/A was recorded as good" 3 days afterapplication and 7 days after application, with a percent defoliation andrating of 85, good" ten days after application, whereas at 2.0 lbs/A,the corresponding ratings were "very good," very good," and In' anothersimilar series of tests conducted in substantially the same manner inArizona against mature Deltapine l6 cotton,the compounds'506 and514'proved to be effective desiccant-defoliants when applied at the rateof 2, 1, 0.5, and 0.25 lbs/Acre using approximately 37 gallons of waterper acre with one pint of nonionic surface active agent X-77 (compoundedproduct of alkyl aryl polyethoxyethanol and free fatty acids- ColloidalProducts Corp.) per gallons. The initial high degree of desiccation fourdays afier treatment, shifting to a high degree of defoliation by 14days after treatment, especially at rata of one pound per acre andhigher, and particularly for compound 5 14, as recorded from the averageof three replicates, showed the compounds to be efiectivedesiccantdefoliants of this particular type of cotton under theconditions encountered. At the 2-lb/A rate, compound 514 was anespecially efiective desiccant.

In another similar series of tests conducted in Texas against maturePaymaster 202 cotton, the compounds 506 and 514 were again shown to beeffective desiccant-defoliants at rates of 0.5, 1.0, and 2.0 lbs/A,being applied in a volume of 14 gals/A using 0.5 percent surfactant(surfactant WK, duPont dodecyl ether of polyethylene glycol).Defoliation and desiccation were evaluated visually after 4 and 1 1days, and figures between 0 and 10 assigned to indicate no apparentresponse to complete defoliation or desiccation. Plots were 2 rows by 40feet, with a blank row between. When statistically evaluated againstnumerous other test compounds, including commercial test compounds,including DEF (TM), Paraquat (TM), and Paraquat (TM) plus Arsenic Acid,after 4 days, 506 was bestand 514 next best as a defoliant (at 2.0 and0.5 lbs./A, respectively); after 11 days, 514 was best as a defoliant(2.0 lbs/A rate), and after 11 days, 506 was best and 514 next best as adesiccant (rates of 0.5 and 0.5 lbs/A, respectively), once againindicating the efiectiveness of the compounds in these respects. Inaddition, as to defoliation, after 4 days, 506 0.5 lb/A) and 514 (2.0lb/A) were tied with others for effectiveness and, afier 11 days, 506(1.0 lb/A) was alone in third place. After 1 1 days 514 (2.0 lb/A) wastied with one another in third place as to desiccation effect. Among thereported conclusions was that, in this test series, low rates of bothcompounds (506 and 514) promoted desiccation that was superior to thatachieved with Paraquat, arsenic acid, combinations of the two, or DEF."In further field and greenhouse tests conducted for the purpose ofobserving degree of suppression of opening of mature cotton bolls, incomparison with Paraquat (TM), Diquat (TM), DEF (TM), and Folex (TM).the compounds 506 and 514 were shown to be at least as effective asthese other commercial products as defoliant-desiccants and were foundto be much superior from the standpoint of not suppressing the openingof mature cotton bolls, a very important consideration as far asfacilitating completeness of picking from individual plants, fields, andyields per acre.

The respective significance of defoliation, desiccation. and wilt willbe immediately apparent to one skilled in the art.

Where stripper cotton harvesting procedures are applied, as in broadcastor close-row plantings, desiccation is preferred as a harvest aidprocedure to eliminate pick-up of defoliated green leaves, i.e., themore desiccation as opposed to defoliation the better for stripperharvesting. Conversely, where spindle harvesting equipment and procedureis the approach of choice, defoliation is definitely the harvest aidprocedure of choice to eliminate as many green leaves as possible fromthe spindle harvester pick-up. Further, as already stated, where anextremely rapid harvest of cotton is desired, rapid wilt permits harvestpromptly after application of the harvest aid, and this procedurepresently holds much promise for commercial application. Whatever thepreferred mode or procedure for aiding harvest, the compounds 506 and514 are clearly suitable and adaptable thereto, without impeding theopening of mature cotton bolls as shown in the foregoing. Obviously, thetime required for effective desiccation and/or defoliation with aparticular agent is also of great interest, and the agents of theinvention are, therefore, also advantageous from the standpoint ofproducing the desired effect in a relatively short period afterapplication.

Where formulated and tested as cotton defoliant-desiccants in the mannerof the foregoing, as reported for 514 and 506, the compounds of Examples4 through 1 l are also shown to be effective and superior cottondefoliant-desiccants.

HERBICIDAL UTILITY The compounds 506 and 514 were provided in the formof percent silica-based wettable powder formulation and were applied byspraying on growing vegetation in a post-emergence procedure at rates ofl, 2 and 3 pounds of such formulation per acre in water using up toabout 100, preferably ap proximately 30-50, gallons of water per acreand approximately one-half to one pint of Colloidal Products Corp.surfactant X-77 (nonionic compounded product of alkyl arylpolyethoxyethanol and free fatty acids) per 100 gallons of Water, thelatter being incorporated just before use. Suitable wettable powdercompositions are identified under the Defoliant-Desiccant" section andare also useful for herbicidal applications.

Pre-plant incorporation and pre-emergence activity was minimal, but thecompounds were very good post-emergence herbicides, giving a high rateof stand reduction and subsequent growth reduction. Regrowth in thepost-emergence plots with both 506 and 514 is much lower than to beexpected from a strictly contact herbicide, e.g., days after treatment,only a few weeds appeared in the 5 l4 post-emergence plots, as shown bytests in Hawaii, the results of which are shown in the following tables,in which the severe damage to or destruction of the growing vegetationis shown in percent:

Chcrnical= CLO-506 application. POST=Post emergenc l 'Iirneapplic PPIPPI PPI PRE PRE PRE POST POST POST Rate .50 1.0 1.5 .50 1.0 1.5 .50 1.01.5 Plot 211 212 213 214 215 216 217 213 219 S G S G S G S G S G S G S SS G S G Alfalfa 0 0 0 0 0 0 0 0 0 0 0 0 Trefoil 0 0 0 0 0 0 0 0 0 0 0 0Redclover 0 0 0 0 0 0 0 0 0 0 0 0 White clover 0 0 0 0 0 0 0 0 0 0 0 0Rape 0 0 0 0 0 0 0 0 0 0 0 0 Broccoli 0 0 0 0 0 O 0 0 0 0 0 0 Carrots-..0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 O O 0 0 0 0 0 0 0 0 0 0 0 0 0 O0 0 0 0 0 0 0 (1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 O O0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Morning g or 0 0 0 0 0 0 00 (J 0 Saffiower. 0 0 0 0 O (I 0 0 0 0 Cotton 0 0 0 0 0 0 0 0 0 0 Wheat-0 0 U 0 0 0 0 0 0 0 Oats 0 0 (1 0 0 0 U 0 0 fl Ryc 0 i] (l (J 0 0 0 0 0ll Barley. 0 0 0 o 0 0 0 0 u 0 Soybeans. 0 0 (J 0 0 0 0 0 0 0 0 ll 0 U 00 U U 0 0 0 0 0 0 0 0 0 0 0 0 0 O 0 0 0 U 0 (1 0 0 0 0 0 fl 0 0 0 0 0 00 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Sugar cane... 0 0 0 0 0 0 0 0 U0 Tomatoes 0 0 0 0 0 0 0 0 O O [S Percent stand reduction, G =Percentgrowth reduction, PII= Chemical: GLC-l514 Pro plant incorporation,PRE=Pre plant application, POST: Post emergence] Time applic PPI PPI PPIPRE IRE PRE POST POST POST ate .50 1.0 1.5 .50 1.0 1.5 .50 1.0 1.5 Plot220 221 222 355 356 358 357 350 360 S G S (i S G S G S (i S (i S G S U SG All lllffl 0 0 0 0 0 0 0 0 0 0 0 0 100 100 100 100 100 Tl'llOlL 0 0 00 0 0 0 0 (l 0 0 0 100 100 100 100 100 l00 Rld (lOVll 0 0 (l 0 (l 0 0 O0 0 O 0 100 100 100 100 lUO lllll White tlOVtl 0 0 0 0 0 0 0 0 0 0 0 01'10 100 100 HX] 100 100 RUDD 0 0 0 0 0 0 0 0 0 0 0 0 $0 0 100 100 100100 BIOCCOll. 0 0 0 0 0 0 0 0 0 ll 0 0 {00 E10 100 100 100 100 CAITOISU0 0 0 0 0 0 0 0 0 0 0 0 100 100 100 100 100 100 Onions u 0 0 0 n 0 0 0 un 0 0 Spinach 0 0 n n 0 0 (1 o 0 n n n 100 100 100 100 lm 100 TABLEVII.-KEKAHA SCREENING TRIAL, KAUAI, HAWAII (HERBICIDES)-Continued lsl'nrccnt stand reduction, (i=lorccnt growth reduction, PPI= application,POST: Post emergence] (lhcnlirnlt (HIP-F114 Pre plant incorporation,PRE=Prc plant 'I'ininn Ii PP] PP] I'II IRE PRE PRE POST POST POSTlt:tl.o. L 1.5 .50 1.0 1.5 .50 1.0 1.5 221 222 355 356 358 357 359 360so so so so so s o s n s E Tomatoes ""zr'n n n""an"n nn'"n'"n"'n"inn"'inn ien inn inn in ice o 0 0 0 0 0 0 0 0 o o 0 100 100100 100 100 100 Annual ryegrass. 0 0 o 0 o o 0 0 o n o o 100 100 100 100100 100 Sugar beets, 0 0 0 0 0 o 0 o 0 o 0 0 no n 100 100 100 100Cucumber- 0 0 0 n 0 o o 0 0 o o 0 an no 100 100 I00 I00 Flax--." 0 o 0 no o n o 0 o 0 o 100 100 100 100 100 Lentils..... 0 0 o o o 0 o 0 o 0 0 0I00 100 100 100 100 100 Morning glor 0 0- 0 o 0 0 u 0 o o 0 o 0 so no so100 100 safflower..- 0 0 o o o 0 u 0 0 o 0 n 100 100 100 100 100 100Cotton... 0 o 0 o o o o o o n o o no 70 I00 100 100 100 Wheat- 0 0 0 0 00 o o 0 o 0 0 100 100 100 I00 100 Oats... 0 o o 0 0 0 0 0 0 0 0 u 100100 100 100 m0 Rye... 0 0 0 0 0 o 0 0 0 0 0 o 100 100 100 100 100Barley... 0 0 0 0 o o 0 o 0 o o o 100 100 100 100 100 Soybeans. o 0 0 00 n 0 0 0 0 0 0 no 90 100 100 100 100 Greenbeans. 0 0 0 0 0 0 0 0 0 0 0.(l 100 100 100 100 I00 eas 0 0 0 0 n o 0 o 0 0 0 o no no I00 100 100 100Field corn..- 0 0 0 0 0 0 0 0 0 0 0 0 90 90 ion 100 loo 100 Sunflower n0 o 0 0 0 0 o 0 0 0 0 00 no 100 100 100 100 In addition, in these sametests, the volunteer weeds TABLE IX Eluesme mdzca and Emrla sonchrfoliawere both completely Tm] results Oregon Eva]. N0 1 destroyed by compound514 at all levels of post-emergence Ch l 514 513 5 emica .l 14.application, whereas compound 506 completely destroyed the Time ofapplication. Post early... Post. early. Post, early latter at allpost-emergence application levels and the former gi t h d f alaplicationBroadcast... Broadcast... Broadcast. to the extent of 9o-7o-9o-so-90-sopercent, with reference E to the foregoing tables. SR GR SR GR SR GR Inwinter screening trials conducted in a similar manner in 90 90 90 no 100mu Oregon, the post-emergence herbicidal activity of S06 and Xl d mustarm i808 i 08 1% 18 0 13 T111118 ryegrass I l l 1 514 wasdemonstrated, the reading being taken 30 days after wild oats 100 100100 100 100 mu application, against oats, rye, barley, and othergrasses, with g g z g H 0 0 2O 3 3 total chlorosis being the ultimatefate of the plant, chlorosis IIIIII: 13g 1% }8g 1% appearing to beprogressive and moving from leaf tips g ey 1 r r x l downward. Theapplication was effected in the same manner Mouseea, Chickweed 100 100100 100 100 100 as given for the foregoing I-Iawanan evaluations. grmtgl bfluegrass 1% igg 10g 100 100 100 e roa ea crops... I 7 70 '6 ."n' Ina similar series of trials conducted in the same manner in Broadleafweeds" 100 100 m0 100 6 100 Texas, the compound 514 showed a very broadspectrum of 40 g ass r p s. 100 100 100 100 in o 100 herbicidal controlin post-emergence evaluations, in which the ee 100 100 100 100 100plants tested (including those mentioned in the following) were at leastsubstantially severely damaged and in most cases completely destroyed.Post-emergence selectivity was shown by 506 as to quackgrass (Agropyronrepens), mullein (verbascum thapsus), and pigweed (Amaranthus sp.) inthe multicropping vegetable areas and ragweed (Ambrosia trifida) insorghum, as well as a pre-emergence selectivity for common lambsquarters(Chenopodium album) at three pounds of percent wettable powder per acre.

In a further series of late-year multicrop screening evaluationsconducted in Oregon in the same manner as given in the foregoing, thecompounds 506 and 514 were found to be effective postemergenceherbicides, substantially severely damaging or completely destroying theplants to which applied. With both 514 and 506, some selectivity wasfound, although activity on broadleaf and weedy grass was nearly 100percent even at the lowest rate. The results are shown in the followingtwo tables, VIII and IX, in which E signifies English TABLE VIII Trialresults Oregon Eval. N0. 1

Chemical 506 506 Time of application. 0st, early Post, earl Post, early.Method of application.... Broadcas Broadcast. Broadcast. Activeingredient/acre.... 0.5 E. 1.0 E 1.5 E.

SR SR GR SR GR Rape 100 100 100 100 100 we Wild mustard- 100 100 100 100100 100 Annual ryegt a 100 100 100 100 100 100 wt oats 100 100 100 100100 100 Common vctch... 30 60 80 70 Oats (Fall)..... no 100 100 100 R100 100 100 100 100 100 100 100 100 100 100 100 Annual blncgrnss. 80 Ill100 100 100 100 lirotullcnl crops... Ni 71; 93 86 93 .10 lirondlcnlWI((lS I00 100 100 100 100 100 (lrnsscrops... 03 .13 I00 100 I00 I00(lrnss wen-(ls. 93 H0 100 100 100 100 units of pounds per acre and SRand GR signify percentage stand reduction and growth reduction,respectively. in addition, some pre-emergence activity against broadleafcrops and weeds and grass crops and weeds was shown by 514 at the 1.5pounds of active ingredient per acre level.

When formulated and tested as herbicides in the manner of the foregoing,as reported for 514 and 506, the compounds of Examples 4 through 6 arealso shown to be efiective herbicides.

The present invention is not to be considered limited to the exactmaterials, compounds, compositions, proportions, methods, or proceduresshown and described, as obvious modifications and equivalents will beapparent to one skilled in the art and the invention is therefore to belimited only by the full scope of the appended claims.

What is claimed is:

l. A dipyridylium dihalide halogen complex of the formula wherein thehalogen of Half has an atomic weight of 35 to 80, inclusive.

3. A compound of claim 1 which is N,N'-ethylene-2,2- dipyn'dyliumbischlorodibromide.

4. A compound of claim 1 which is N,N'-ethylene-2,2- dipyridyliumbistribromide.

5. N,N-ethylene-2,2'-dipyridylium bistrihalide wherein the halogen has aatomic weight from 35 to 80, inclusive.

' columns, in the Heading of the Table: Delete "H -1 and insert Hal;

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3,674,788 Dated July 4, 1972 I Inventofls) Robert MlThomas, Fred R.Gerns, and John L. Sands It is certified that error appears in theabove-identified patent and that said Letters Patent are herebycorrected as shown below:

Column 3, in the Table, Compounds 8, 9, and 10 in the "Y" column:

' Delete "C H in each occurrence and insert C H in each occurrence.

Column 5, line 24: After "962 g." insert an asterisk after line 26:

column 6, Table II, under b. Melting Points, (95% titer," should read(95% Br titer,

Column ll, line 24: Cancel "11" and insert 6 In Table VI, the column inthe Table entitled "POST .50

217 v r S. 8.", the "S" in the second occurrence should be "G". ,1

In Table VII, the columns in the Table reading "PRE "POST 1.5 and .50358" 357" should read:

--PRE POST 1.5 and .50 357 358 In Table IX (column 14 of the patent),under the heading 'Oregon" the number "513" should read 514 t In column14, line 76 (Claim 5) cancel "a" and insert an Insert *Ccmbined yield oftwo replicate reactionsl Signed and sealed this 26th dayof December1972.

A t 2st:

EDWARD M.,FLETCHEIR,JR.. Attesting Officer ROBERT GOTTS CHALKCommissioner of Patents

2. A compound of Claim 1 having the formula
 3. A compound of claim 1which is N,N''-ethylene-2,2''-dipyridylium bischlorodibromide.
 4. Acompound of claim 1 which is N,N''-ethylene-2,2''-dipyridyliumbistribromide.
 5. N,N''-ethylene-2,2''-dipyridylium bistrihalide whereinthe halogen has a atomic weight from 35 to 80, inclusive.